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[JOB] Two postdoctoral positions for the modeling of alkaline electrolysis

Join the CEA/TotalEnergies collaboration DAWN, and contribute to the development of a digital twin for the production of green dihydrogen with alkaline electrolysers. We are recruiting two postdoctoral researchers to develop the numerical tools Flower and canoP for a period of 2 years to work at our CEA Saclay site near Paris.

To apply, please send your application (resume and cover letter) to Pascal Tremblin and Taraneh Sayadi. You can use the same addresses for any questions concerning the offer. Applications will be evaluated until the positions are filled.

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[JOB] C++ expert engineer 👩‍💻🧑‍💻- Contribution to the development of the Kokkos GPU computing library within the CExA “Moonshot” project

Join the CEA’s ambitious “Moonshot” project, CExA, and contribute to the development of the Kokkos GPU computing library. We are recruiting six talented and enthusiastic C++ development engineers for a period of 2 years to work at our CEA Saclay site near Paris.

To apply, please send your application (resume and cover letter) to You can use this same address for any questions concerning the offer. Applications will be evaluated from mid-May until the position is filled.


Europe is investing to build exaflop supercomputers in the coming years, including one in France, at the CEA, in 2025. These machines will be heterogeneous, accelerated by GPUs of various brands and architectures. Ensuring performance and portability under these conditions is certainly one of the greatest challenges of the Exascale. To address it, CEA is investing heavily in an ambitious “Moonshot” project: CExA. In this project, we will setup libraries to fully exploit this computing power in the scientific applications of the CEA by contributing, extending and adapting the open-source library Kokkos. Within CExA, we represent teams with expertise in numerical computation from the four components of the CEA.

  • Maison de la Simulation of the DRF is a joint research and engineering laboratory of CEA, CNRS, Univ. Paris-Saclay and UVSQ specialized in high performance computing and numerical simulation.
  • The DES’s software engineering department for simulation brings together three laboratories that address the issues of simulation environment, AI and data science, high performance computing and numerical analysis.
  • The DSCIN at DRT/LIST is responsible for the research and development of digital integrated circuits and processors for AI, as well as the design of complex digital architectures. It also works on solutions for embedded systems and develops design tools for embedded AI, embedded systems and trusted circuits.
  • The DSSI of the DAM manages activities in the fields of computer science, applied mathematics and information systems, covering a wide spectrum from definition and design to user services.


As part of a new agile team being set up to carry out the CExA project, you will work in collaboration with the European HPC ecosystem and the teams in charge of the development of Kokkos in the United States (Sandia and Oakridge National labs). You will enrich the library to fit the needs of the CEA applications and to the technologies developed by Europe for the Exascale (EPI, SiPearl, RISC-V)

Your mission will include:

  • Agile development in C++ of the CExA middleware to address the following areas of improvement:
    • Adaptation to “distributed memory” architectures
    • Support for heterogeneous architectures for European exaflop supercomputers
    • Interfacing with external libraries and data processing tools
    • Simplification of deployment
  • Porting via Kokkos and integration of new functionalities in selected application demonstrators (hydrodynamics, fusion energy, AI-assisted medicine)
  • Support and animation on parallel programming models within the laboratory and at the scale of European and global collaborations.


You have a master and/or an engineering degree in computer science and:

  • You have a solid knowledge of advanced C++ and the latest standards.
  • You know how to fit into an agile development process (SCRUM) and you master the basic tools associated with collaborative development (git, github, etc.).
  • You have skills in software engineering. You are familiar with common development environments and associated tools (cmake, docker, spack, gtest, ctest, etc.).
  • Knowledge of parallel programming (GPU, multi-threaded, etc.) is a plus, especially with the Kokkos library or equivalent.
  • You are autonomous and you wish to be part of an international work team. You master technical English (written and oral). You are interested in the world of high-performance computing and its challenges and follow the evolution of technologies.

Salary and benefits

The CEA offers salaries based on your degrees and experience.

This position offers several advantages:

  • the possibility to join collaborations with other European laboratories, the United States and Japan,
  • Numerous opportunities to travel internationally (exchanges, conferences, workshops and more)
  • Up to 3 days of telecommuting per week
  • Reimbursement of up to 75% of public transport cards and a free transport network throughout the Ile-de-France region,
  • An interesting complementary health insurance and several company savings plans,
  • 5 weeks of paid vacation and 4 weeks of RTT per year.
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[JOB] Permanent Researcher Position

System software for in situ HPC/AI coupling

Maison de la Simulation (MdlS) recruits a permanent CEA researcher (ingĂ©nieur chercheur permanent) to reinforce its “Science of Computing” (SoC) team.

In order to apply, please send a resume, cover letter, references and support letters to You can use the same email address for requests of information about the position. Applications will be evaluated from May the 15th 2023 and until the position is filled.


Maison de la Simulation is a joint research and engineering laboratory of CEA, CNRS, Université Paris-Saclay and Université de Versailles Saint-Quentin-en-Yvelines localized on the plateau de Saclay campus next to Paris. It specializes in high-performance computing. The “Science of Computing” team conducts research, builds expertise and engineers tools in domains underlying HPC: computer science and applied mathematics.

The team co-leads the 5-years French ExaDoST project, part of NumPEx, that will design the software stack for data handling on the upcoming French and potentially European Exascale super-computers.


During the first five years, the selected candidate will contribute to the ExaDoST project. They will conduct research and design tools for data handling at Exascale, working both on the user facing API and on system software for in situ HPC/AI coupling. They will work in close collaboration with the other members of the project to design a modular software stack that should be used on the upcoming French Exascale supercomputer as well as more globally on French, European, and worldwide supercomputers.

To achieve these goals, the candidate will take part in the recruitment and management of the group of temporary engineer and young researchers dedicated to this project. They will leverage the expertise and tools already developed in the team, including the PDI and Deisa libraries.

As time evolves, the selected candidate will develop their own research and projects in the domains of the team. At the conclusion of ExaDost, they will have a large latitude to direct their research toward the directions they feel would serve the team and laboratory best.

Main activities

The candidate will:

  • conduct their research in the domain of runtime and system software for in situ analytics and HPC/AI coupling,
  • take part in the design and implementation of libraries and tools that make the results of this research available to users of HPC in production,
  • take part in the NumPEx project, and related activities of management and reporting,
  • participate to the management of temporary engineers and young researchers.

Skills and competencies

The successful candidate will hold a PhD thesis in computer science or in another field with a strong experience in computer science. They should master the following skills and competencies:

  • good knowledge of HPC parallel architectures, operating systems, and application programming,
  • knowledge of the design of existing system tools and libraries for HPC data handling (IO, in situ processing, coupling, checkpoint writing, etc.),
  • good programming skills in C++, and associated developments tools (Cmake, git, etc.),
  • good programming skills in python, and associated ecosystem,
  • autonomy, interest for team-work in an international context, leadership.

Salary and advantages

CEA “ingénieur-chercheur” positions offer a very competitive salary in French research ecosystem, indexed on diplomas and experience. In addition, the selected candidate will benefit from many advantages:

  • possibility to leverage existing collaborations of MdlS in Europe, US and Japan as well as international conferences with support for travel,
  • up to 3 days of remote work per week,
  • reimbursement of public transport costs (75%) and subsidized catering service,
  • included pension plan and health coverage (French social security plus CEA-specific insurance),
  • 9 full weeks of holidays per year.